This invention relates generally to analog wristwatch movements with additional features such as calendar mechanisms and which are adapted for ease of assembly. More particularly, the invention concerns an improved analog wristwatch movement with a special holding plate to organize the unattached gear train members into an easily transportable movement, to retain additional elements needed in a day/date calendar watch, to provide the detenting functions needed for a day disc and date ring in a calendar watch, and to provide spring loading functions to prevent damage to the setting mechanism.
Some types of analog wristwatch movements are designed to be assembled in situ into a watch case, adding unattached elements such as hour wheel, center wheel and minute wheel at the time of assembly before adding the watch dial. More complex watch assemblies with day/date calendar functions require the addition of more unattached components at the time of in situ assembly. This complicates the assembly process when the movement has to be transported between various work stations for operations in the factory, or when it must be packaged and shipped to another location for additional assembly work. It would be desirable to have the unattached components used in a day/date calendar watch, such as detent springs, date ring, day disc, all held in place so that the movement could be assembled into a watch case without undue difficulty.
The date ring and day disc used in day/date calendar mechanisms require spring loaded detenting members. Detent springs are sometimes supplied as separate members. It would be desirable to incorporate the detent springs and detent members into another member to reduce the number of parts.
Other functions are performed by special spring elements in an analog wristwatch movement to prevent damage. One example is the setting mechanism, in which a stem with a setting pinion is slidable within the movement to engage crown teeth on a setting wheel, which is permanently meshed with the timepiece gear train. In order to prevent damage, constructions are known in which the setting wheel is restrained by a spring member and allowed to move during engagement of the gear teeth in order to prevent damage.
An example of a day/date calendar watch utilized in a mechanical movement previously manufactured by applicant's assignee is shown in U.S. Pat. No. 3,859,783 issued to P. Wuthrich on Jan. 14, 1975. That patent shows a day/date wheel driven by the normal timekeeping gear train in a mechanical wristwatch to rotate once per day and to advance both a date ring and a day disc, each provided with its own separate detent spring.
U.S. No. Pat. 5,083,300 issued to H. Schwartz on Jan. 21, 1992 and assigned to applicant's assignee shows a timepiece setting mechanism including a yieldable support member to allow the minute wheel to move and prevent damage when its crown teeth are engaged by the setting pinion of the setting mechanism.
It would be desirable to provide a single multifunctional member which could accomplish all of the foregoing functions.
Accordingly, one object of the present invention is to provide a multifunctional holding plate, which will organize and hold in place a number of otherwise unattached gear train members and day/date calendar watch members in a wristwatch movement.
Another object of the invention is to provide a multifunctional holding plate which incorporates the spring loaded detent functions in a day/date calendar watch.
Another object of the present invention is to provide a multifunctional holding plate which incorporates a yieldable spring member to prevent damage to the setting mechanism.